Electric motors are used in bicycles both as a full drive and as an auxiliary or hybrid drive, the electric motor, when required, acting either as a complete bicycle drive or to assist the pedal drive actuated by the cyclist. As sources of energy for such a motor, batteries, more particularly rechargeable batteries are required, which are conventionally fastened to the bicycle frame in a suitable location. To this end, the bicycle frame is usually provided with a battery container. However, such a battery container is relatively bulky and not only reduces the free space otherwise available on the bicycle frame, particularly for accommodating additional equipment such as water bottles, bicycle tools, etc., but may even impair the cycling comfort for the cyclist in the extreme case. In addition, securing the battery inside such a container also represents a problem since it has a significant own weight but occasionally has to withstand hard shocks during cycling.
EP 0 905 014 B1 discloses a motor-driven folding bicycle in the rear frame section of which a battery for its electric drive is stored. When the front frame section is folded around the rear frame section, a frontal opening on the front side of the rear frame section is uncovered through which the battery compartment is accessible from the outside. However, such a frontal opening is only convenient in folding bicycles since the front side of a non-folding bicycle is normally covered by the bicycle lights, the brake lines, etc., and is only insufficiently accessible. Furthermore, the possibility of securing the battery in the frame interior is also limited by this frontal opening. For a reliable battery retention that is also protected against hard shocks of the frame a force application to the battery in the longitudinal direction of the frame would be necessary. However, since the frontal frame opening requires a manual insertion of the battery against the action of such a force, only relatively small retaining forces may be employable in such a battery holder.